Study of teratologic effects of zonisamide on neonatal rat skeletal system

Zonisamide is one of the most effective medications for epilepsy, which has teratogenic properties; and is widely administrated in patients. The present study aimed to evaluate the teratogenic effects of zonisamide on newborn rats’ skeletal system during fetal period. Therefore, 12 mature male rats were mated with 36 female rats and the female rats became pregnant. The pregnant rats were randomly divided into two equal groups of treatment and control.. The treatment group received 200 mg/kg zonisamide on days 9, 10, and 11 of pregnancy via gavage. The control group also received the same amount of normal saline solution on the same days of pregnancy via gavage. Length and weight of the newborn rats were measured using caliper and digital weigh. Then, the newborns were evaluated in terms of apparent anomalies under the stereomicroscope. Eventually, Alizarin Red staining was conducted in order to study bones. Data were analyzed using T-test. The mean length of arm, ulna, radius, thigh, tibia, and fibula was significantly different between the two groups. Alizarin Red results suggested that the treatment group had anomalies such as scoliosis, wavy rib, imperfectly formed bones of the skull. The results of the study indicated that administration of zonissamide during pregnancy causes fetal growth disorders and retards fetal growth therefore it is considered as a risk factor for fetal development in this species. Conflict of interest: None declared.